Method and apparatus for handling measurement gaps in wireless networks

ABSTRACT

In a wireless communication system, user equipment (UE) has autonomy provided by one or more set of rules to handle processing during a measurement gap. UE can ignore or use only a portion of the whole measurement gap if not needed. Thereby, an urgent need for remaining tuned to source carrier frequency can be supported, such as utilizing Random Access Channel (RACH) procedure. UE can also choose to tune to a target carrier frequency supporting timely handovers. Depending on the type of processing required (download shared channel (DL-SCH, UL-SCH, TTI bundling, RACH or SR), the UE may store requests and process the measurements during the gap or ignore the gap measurement as if there were no gaps.

CLAIM OF PRIORITY UNDER 35 U.S. C. § 119

The present Application for Patent claims priority to ProvisionalApplication No. 61/087,541 entitled “Method and Apparatus for HandlingMeasurement Gaps in Wireless Communication System” filed Aug. 8, 2008,assigned to the assignee hereof and hereby expressly incorporated byreference herein.

CROSS REFERENCE TO RELATED APPLICATIONS

The present Application is related to co-pending and commonly assignedU.S. Patent Application Number (Attorney Docket 082359) entitled“Processing Measurement Gaps In A Wireless Communication System” filedon even date herewith, which in turn claims priority to ProvisionalApplication Number 61/087,930 entitled “A Method and Apparatus forProcessing Measurement Gaps in a Wireless Communication System” filedAug. 11, 2008, the disclosures of both of which are hereby expresslyincorporated by reference in their entirety.

FIELD OF INVENTION

The exemplary and non-limiting aspects described herein relate generallyto wireless communications systems, methods, computer program productsand devices, and more specifically to techniques for processingmeasurement gaps.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustypes of communication content such as voice, data, and so on. Thesesystems may be multiple-access systems capable of supportingcommunication with multiple users by sharing the available systemresources (e.g., bandwidth and transmit power). Examples of suchmultiple-access systems include code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, and orthogonal frequencydivision multiple access (OFDMA) systems.

Generally, a wireless multiple-access communication system cansimultaneously support communication for multiple wireless terminals.Each terminal communicates with one or more base stations viatransmissions on the forward and reverse links. The forward link (ordownlink) refers to the communication link from the base stations to theterminals, and the reverse link (or uplink) refers to the communicationlink from the terminals to the base stations. This communication linkmay be established via a single-in-single-out, multiple-in-signal-out ora multiple-in-multiple-out (MIMO) system.

Universal Mobile Telecommunications System (UMTS) is one of thethird-generation (3G) cell phone technologies. UTRAN, short for UMTSTerrestrial Radio Access Network, is a collective term for the Node-B'sand Radio Network Controllers which make up the UMTS core network. Thiscommunications network can carry many traffic types from real-timeCircuit Switched to IP based Packet Switched. The UTRAN allowsconnectivity between the UE (user equipment) and the core network. TheUTRAN contains the base stations, which are called Node Bs, and RadioNetwork Controllers (RNC). The RNC provides control functionalities forone or more Node Bs. A Node B and an RNC can be the same device,although typical implementations have a separate RNC located in acentral office serving multiple Node B's. Despite the fact that they donot have to be physically separated, there is a logical interfacebetween them known as the Iub. The RNC and its corresponding Node Bs arecalled the Radio Network Subsystem (RNS). There can be more than one RNSpresent in an UTRAN.

3GPP LTE (Long Term Evolution) is the name given to a project within theThird Generation Partnership Project (3GPP) to improve the UMTS mobilephone standard to cope with future requirements. Goals include improvingefficiency, lowering costs, improving services, making use of newspectrum opportunities, and better integration with other openstandards. The LTE system is described in the Evolved UTRA (EUTRA) andEvolved UTRAN (EUTRAN) series of specifications.

Measurement gaps are assigned by a network, such as a source basestation, to user equipment so that user equipment (UE) can tune from asource carrier frequency to target carrier frequency to performmeasurements. This can be particularly helpful for UE that lacks a dualmode receiver. Thereby, mobility of UE is facilitated by being able tomore quickly perform a handover when required or advantageous.

SUMMARY

The following presents a simplified summary in order to provide a basicunderstanding of some aspects of the disclosed aspects. This summary isnot an extensive overview and is intended to neither identify key orcritical elements nor delineate the scope of such aspects. Its purposeis to present some concepts of the described features in a simplifiedform as a prelude to the more detailed description that is presentedlater.

In accordance with one or more aspects and corresponding disclosurethereof, various aspects are described in connection with techniques forhandling measurement gaps. When measurement gap duration is for a fixed,predetermined amount of time (e.g., 6 ms) in an assignment from anetwork entity to user equipment (UE), the UE advantageously has freedomto vary its effective measurement gap instead of having a fixed timeperiod for the gap. Thereby, the actual duration of the measurement candepend on the type of a target Radio Access Technology (RAT) to measure,which for some RAT can take less than 6 ms. Also, depending on powersaving (e.g., Discontinuous Reception—DRX) configuration, the UE may beable to perform supplementary measurements at different times. As longas the ULE meets predetermined performance requirements (e.g.,measurement performance), the UE should be allowed to measure only asmuch as it needs. When not performing measurement, the UE should be ableto perform transmissions on its serving cell.

In one aspect, a method is provided for utilizing a measurement gap bywirelessly communicating on a source carrier frequency, receiving anassignment for a measurement gap on the source carrier frequency,independently determining to remain tuned to the source carrierfrequency during at least a portion of the measurement gap, andselectively tuning between the source carrier frequency and a targetcarrier frequency during the measurement gap in accordance with theindependent determination.

In another aspect, at least one processor is provided for utilizing ameasurement gap. A first module wirelessly communicates on a sourcecarrier frequency. A second module receives an assignment for ameasurement gap on the source carrier frequency. A third moduleindependently determines to remain tuned to the source carrier frequencyduring at least a portion of the measurement gap. A fourth moduleselectively tunes between the source carrier frequency and a targetcarrier frequency during the measurement gap in accordance with theindependent determination.

In an additional aspect, a computer program product is provided forutilizing a measurement gap. A computer-readable storage mediumcomprises sets of code for causing a computer to wirelessly communicateon a source carrier frequency, to receive an assignment for ameasurement gap on the source carrier frequency, to independentlydetermine to remain tuned to the source carrier frequency during atleast a portion of the measurement gap, and to selectively tune betweenthe source carrier frequency and a target carrier frequency during themeasurement gap in accordance with the independent determination.

In another additional aspect, an apparatus is provided for utilizing ameasurement gap. Means are provided for wirelessly communicating on asource carrier frequency. Means are provided for receiving an assignmentfor a measurement gap on the source carrier frequency. Means areprovided for independently determining to remain tuned to the sourcecarrier frequency during at least a portion of the measurement gap.Means are provided for selectively tuning between the source carrierfrequency and a target carrier frequency during the measurement gap inaccordance with the independent determination.

In a further aspect, an apparatus is provided for utilizing ameasurement gap. A transmitter wirelessly communicates on a sourcecarrier frequency. A receiver receives an assignment for a measurementgap on the source carrier frequency. A computing platform independentlydetermines to remain tuned to the source carrier frequency during atleast a portion of the measurement gap, wherein the computing platformis further for selectively tuning the transmitter between the sourcecarrier frequency and a target carrier frequency during the measurementgap in accordance with the independent determination.

In yet one aspect, a method is provided for assigning a measurement gapby wirelessly communicating on a source carrier frequency, transmittingan assignment for a measurement gap on the source carrier frequency, andfacilitating user equipment to independently determine to remain tunedto the source carrier frequency during at least a portion of themeasurement gap and to selectively tune between the source carrierfrequency and a target carrier frequency during the measurement gap inaccordance with the independent determination.

In yet another aspect, at least one processor is provided for assigninga measurement gap. A first module wirelessly communicates on a sourcecarrier frequency. A second module receives an assignment for ameasurement gap on the source carrier frequency. A third moduleindependently determines to remain tuned to the source carrier frequencyduring at least a portion of the measurement gap. A fourth moduleselectively tunes between the source carrier frequency and a targetcarrier frequency during the measurement gap in accordance with theindependent determination.

In yet an additional aspect, a computer program product is provided forassigning a measurement gap. A computer-readable storage mediumcomprises sets of codes for causing a computer to wirelessly communicateon a source carrier frequency, to transmit an assignment for ameasurement gap on the source carrier frequency, to facilitate userequipment to independently determine to remain tuned to the sourcecarrier frequency during at least a portion of the measurement gap, andto selectively tune between the source carrier frequency and a targetcarrier frequency during the measurement gap in accordance with theindependent determination.

In yet another additional aspect, an apparatus is provided for assigninga measurement gap. Means are provided for wirelessly communicating on asource carrier frequency. Means are provided for transmitting anassignment for a measurement gap on the source carrier frequency. Meansare provided for facilitating user equipment to independently determineto remain tuned to the source carrier frequency during at least aportion of the measurement gap, and to selectively tune between thesource carrier frequency and a target carrier frequency during themeasurement gap in accordance with the independent determination.

In yet a further aspect, an apparatus is provided for assigning ameasurement gap. A receiver wirelessly communicates on a source carrierfrequency. A transmitter transmits an assignment for a measurement gapon the source carrier frequency. A computing platform independentlydetermines to remain tuned to the source carrier frequency during atleast a portion of the measurement gap, wherein the user equipmentselectively tunes its transmitter between the source carrier frequencyand a target carrier frequency during the measurement gap in accordancewith its independent determination.

To the accomplishment of the foregoing and related ends, one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative aspectsand are indicative of but a few of the various ways in which theprinciples of the aspects may be employed. Other advantages and novelfeatures will become apparent from the following detailed descriptionwhen considered in conjunction with the drawings and the disclosedaspects are intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The features, nature, and advantages of the present disclosure willbecome more apparent from the detailed description set forth below whentaken in conjunction with the drawings in which like referencecharacters identify correspondingly throughout and wherein:

FIG. 1 illustrates a block diagram of a communication system.

FIG. 2 illustrates a timing diagram of options facilitated by a networkand performed by user equipment to exercise independence in utilizingmeasurement gaps.

FIG. 3 illustrates a methodology or sequence of operations facilitatedby a network and performed by user equipment to exercise independence inutilizing measurement gaps.

FIG. 4 illustrates a diagram of a multiple access wireless communicationsystem according to one aspect for utilizing measurement gaps.

FIG. 5 illustrates a schematic block diagram of a communication systemfor utilizing measurement gaps.

FIG. 6 illustrates a schematic block diagram of a base station and userequipment wirelessly communicating to utilize measurement gaps.

FIG. 7 illustrates a system comprising logical grouping of electricalcomponents for utilizing measurement gaps.

FIG. 8 illustrates a system comprising logical grouping of electricalcomponent for facilitating user equipment to utilize measurement gaps.

FIG. 9 illustrates a flow diagram of a methodology or sequence ofoperations for user equipment to utilize measurement gaps facilitated bya wireless network.

FIG. 10 illustrates a block diagram for an apparatus for utilizing ameasurement gap.

FIG. 11 illustrates a block diagram for an apparatus for assigningmeasurement gaps.

DETAILED DESCRIPTION

In a wireless communication system, user equipment (UE) has autonomyprovided by one or more set of rules to handle processing during ameasurement gap. A measurement gap is a time interval provided so that aserved UE can prepare for handover to a different Radio AccessTechnology (RAT) in a different frequency and wavform. UE can ignore oruse only a portion of the whole measurement gap if not needed. Thereby,an urgent need for remaining tuned to source carrier frequency can besupported, such as utilizing Random Access Channel (RACH) procedure. UEcan also choose to tune to a target carrier frequency supporting timelyhandovers. Depending on the type of processing required, the UE maystore requests and process the measurements during the gap or ignore thegap measurement as if there were no gaps. Examples of types ofprocessing include download shared channel (DL SCH), Uplink sharedchannel (UL SCH), Hybrid Automatic-Repeat-Request (HARQ) transmissionsduring Transmission Time Interval (TTI) bundling, RACH processing orService Request (SR).

Various aspects are now described with reference to the drawings. In thefollowing description, for purposes of explanation, numerous specificdetails are set forth in order to provide a thorough understanding ofone or more aspects. It may be evident, however, that the variousaspects may be practiced without these specific details. In otherinstances, well-known structures and devices are shown in block diagramform in order to facilitate describing these aspects.

Referring initially to FIG. 1, a communication system 100 comprises asource Radio Access Technology (RAT), comprising a base station,depicted as an evolved Node B (eNB) 102, which communicates via anover-the-air (OTA) link 104 with user equipment (UE) 106. To facilitatemobility with uninterrupted communication sessions, the UE 106advantageously can take measurements of broadcasts 108 by a target basestation, depicted as measured eNB 110. In some instances, the UE 108features only one receiver 112 and thus lacks a second receiver 114 thatcould tune to a target carrier frequency of the target eNB 110 while thefirst receiver 112 remains tuned to the source carrier frequency. In ahighly scheduled wireless communication protocol, it is thusadvantageous that the source eNB 102 assign measurement gaps 116 on adownlink (DL) 118 to the UE 106. During a measurement gap, the UE maytune away from the source base station. Advantageously, the UE 106 hasan independent measurement gap usage component 120 that can determinewhether or not to use all or part of the assigned measurement gap.Instead, the UE 106 can monitor, on the source RAT, the DL 118 orperform Uplink (UL) communication 122 on an Uplink 124 during some orall of the measurement gap.

In FIG. 2, timing parameters 200 are depicted for a measurement gap 202according to one aspect, which can be a fixed period. In a first OptionA 204 for deciding to comply with a measurement gap, a ULE operates at asource frequency (SF) 206 until start time (TI) 208. At start time 208,the UE switches to a target frequency (TF) 210 until stop time (T2) 212.The measurement gap 202 is thus defined by the start time (T1) 208 andthe stop time (T2) 212.

In an Option B 214 illustrating late departure time (LTD) 216 accordingto one aspect, a UE operates at the source frequency (SF) 206 until atime of late departure (LDT) 216. It is noted that the time of latedeparture (LDT) 216 is after the start time 208. At time of latedeparture (LDT) 216, the UE switches to the target frequency (TF) 210until stop time (T2) 212. An effective measurement gap 220 in the caseof late departure is defined by the time of late departure (LDT) 216 andthe stop time 212.

In an Option C 222 illustrating early return time (ERT) 224 according toanother aspect, UE operates at the source frequency (SF) 206 until starttime (TI) 208. At the start time 208, the UE switches to the targetfrequency (TF) 210 until the time of early return (ERT) 224. It is notedthat the time of early return (ERT) 224 is before the stop time 212. Aneffective measurement gap 226 in the case of late departure is definedby the start time 208 and the time of early return (ERT) 224.

In an Option D 228 illustrating a canceled departure 230 according toanother aspect, there is no measurement gap since the UE stays at thesource frequency 206 and does not switch to a target frequency 210.

In an Option E 232 illustrates both a late departure time (LDT) 234 andan early return 236 defining an effective measurement gap 238 is definedby the late departure time (LDT) 234 and the early return time (ERT)236.

In FIG. 3, a methodology or sequence of operations 300 is depictedbetween UE 302, a source eNB 304, and a target eNB 306. The source eNB304 sends measurement gap scheduling to the UE 302 as depicted at 310.The UE 302 makes a determination as to what needs it has to communicateon the source frequency during the assigned measurement gap (block 312).The UE 302 further makes a determination as to its measurement needs onthe target frequency during the measurement gap (block 314). Based uponbalancing these needs, the UE 302 selects to use all, a portion, or noneof the measurement gap (block 316). In block 320, the eNB 304facilitates this independence of the UE 302 to tune to a targetfrequency (block 321) using a selective portion 322 of assignedmeasurement gap 324. In particular, the eNB 304 can receive uplinkcommunication from the UE 302 made during assigned measurement gap asdepicted at 326. The eNB 304 then processes the UL transmission (block328). The source eNB 304 can also attempt to transmit urgent downlinktransmission during the measurement gap (block 330), in the hopes thatthe UE 302 can receive the transmission even in the measurement gap at332.

It should be appreciated that wireless communication systems are widelydeployed to provide various types of communication content such asvoice, data, and so on. These systems may be multiple-access systemscapable of supporting communication with multiple users by sharing theavailable system resources (e.g., bandwidth and transmit power).Examples of such multiple-access systems include code division multipleaccess (CDMA) systems, time division multiple access (TDMA) systems,frequency division multiple access (FDMA) systems, and orthogonalfrequency division multiple access (OFDMA) systems.

Generally, a wireless multiple-access communication system cansimultaneously support communication for multiple wireless terminals.Each terminal communicates with one or more base stations viatransmissions on the forward and reverse links. The forward link (ordownlink) refers to the communication link from the base stations to theterminals, and the reverse link (or uplink) refers to the communicationlink from the terminals to the base stations. This communication linkmay be established via a single-in-single-out, multiple-in-signal-out ora multiple-in-multiple-out (MIMO) system.

A MIMO system employs multiple (N_(T)) transmit antennas and multiple(N_(R)) receive antennas for data transmission. A MIMO channel formed bythe N_(T) transmit and NR receive antennas may be decomposed into N_(S)independent channels, which are also referred to as spatial channels,where N_(S)≦min {N_(T), N_(R)} Each of the N_(S) independent channelscorresponds to a dimension. The MIMO system can provide improvedperformance (e.g., higher throughput and/or greater reliability) if theadditional dimensionalities created by the multiple transmit and receiveantennas are utilized.

A MIMO system supports a time division duplex (TDD) and frequencydivision duplex (FDD) systems. In a TDD system, the forward and reverselink transmissions are on the same frequency region so that thereciprocity principle allows the estimation of the forward link channelfrom the reverse link channel. This enables the access point to extracttransmit beamforming gain on the forward link when multiple antennas areavailable at the access point.

Referring to FIG. 4, a multiple access wireless communication systemaccording to one aspect is illustrated. An access point 450 (AP) or basestation, or eNB includes multiple antenna groups, one including 454 and456, another including 458 and 460, and an additional including 462 and464. In FIG. 4, only two antennas are shown for each antenna group,however, more or fewer antennas may be utilized for each antenna group.A user equipment (UE) or access terminal (AT) 466 is in communicationwith antennas 462 and 464, where antennas 462 and 464 transmitinformation to access terminal 466 over forward link 470 and receiveinformation from access terminal 466 over reverse link 468. Accessterminal 472 is in communication with antennas 456 and 458, whereantennas 456 and 458 transmit information to access terminal 472 overforward link 476 and receive information from access terminal 472 overreverse link 474. In a FDD system, communication links 468, 470, 474 and476 may use different frequency for communication. For example, forwardlink 470 may use a different frequency then that used by reverse link468. Each group of antennas and/or the area in which they are designedto communicate is often referred to as a sector of the access point 450.In the aspect, antenna groups each are designed to communicate to accessterminals 466, 472 in a sector of the areas covered by access point 450.

In communication over forward links 470 and 476, the transmittingantennas of access point 450 utilize beamforming in order to improve thesignal-to-noise ratio of forward links for the different accessterminals 466 and 474. Also, an access point using beamforming totransmit to access terminals scattered randomly through its coveragecauses less interference to access terminals in neighboring cells thanan access point transmitting through a single antenna to all its accessterminals.

An access point 450 may be a fixed station used for communicating withthe terminals and may also be referred to as an access point, a Node B,or some other terminology. An access terminal 466, 472 may also becalled user equipment (UE), a wireless communication device, terminal,access terminal or some other terminology.

FIG. 5 is a block diagram of an aspect of a transmitter system 510 (alsoknown as the access point) and a receiver system 550 (also known asaccess terminal) in a MIMO system 500. At the transmitter system 510,traffic data for a number of data streams is provided from a data source512 to a transmit (TX) data processor 514.

In an aspect, each data stream is transmitted over a respective transmitantenna. TX data processor 514 formats, codes, and interleaves thetraffic data for each data stream based on a particular coding schemeselected for that data stream to provide coded data.

The coded data for each data stream may be multiplexed with pilot datausing OFDM techniques. The pilot data is typically a known data patternthat is processed in a known manner and may be used at the receiversystem to estimate the channel response. The multiplexed pilot and codeddata for each data stream is then modulated (i.e., symbol mapped) basedon a particular modulation scheme (e.g., BPSK, QSPK, M-PSK, or M-QAM)selected for that data stream to provide modulation symbols. The datarate, coding, and modulation for each data stream may be determined byinstructions performed by processor 530 utilizing memory 532.

The modulation symbols for all data streams are then provided to a TXMIMO processor 520, which may further process the modulation symbols(e.g., for OFDM). TX MIMO processor 520 then provides NT modulationsymbol streams to N_(T) transmitters (TMTR) 522 a through 522 t. Incertain implementations, TX MIMO processor 520 applies beamformingweights to the symbols of the data streams and to the antenna from whichthe symbol is being transmitted.

Each transmitter 522 receives and processes a respective symbol streamto provide one or more analog signals, and further conditions (e.g.,amplifies, filters, and upconverts) the analog signals to provide amodulated signal suitable for transmission over the MIMO channel. N_(T)modulated signals from transmitters 522 a through 522 t are thentransmitted from N_(T) antennas 524 a through 524 t, respectively.

At receiver system 550, the transmitted modulated signals are receivedby N_(R) antennas 552 a through 552 r and the received signal from eachantenna 552 is provided to a respective receiver (RCVR) 554 a through554 r. Each receiver 554 conditions (e.g., filters, amplifies, anddownconverts) a respective received signal, digitizes the conditionedsignal to provide samples, and further processes the samples to providea corresponding “received” symbol stream.

An RX data processor 560 then receives and processes the NR receivedsymbol streams from N_(R) receivers 554 based on a particular receiverprocessing technique to provide N_(T) “detected” symbol streams. The RXdata processor 560 then demodulates, deinterleaves, and decodes eachdetected symbol stream to recover the traffic data for the data stream.The processing by RX data processor 560 is complementary to thatperformed by TX MIMO processor 520 and TX data processor 514 attransmitter system 510.

A processor 570 periodically determines which pre-coding matrix to use(discussed below). Processor 570 formulates a reverse link messagecomprising a matrix index portion and a rank value portion, utilizingmemory memory 572.

The reverse link message may comprise various types of informationregarding the communication link and/or the received data stream. Thereverse link message is then processed by a TX data processor 538, whichalso receives traffic data for a number of data streams from a datasource 536, modulated by a modulator 580, conditioned by transmitters554 a through 554 r, and transmitted back to transmitter system 510.

At transmitter system 510, the modulated signals from receiver system550 are received by antennas 524, conditioned by receivers 522,demodulated by a demodulator 540, and processed by a RX data processor542 to extract the reserve link message transmitted by the receiversystem 550. Processor 530 then determines which pre-coding matrix to usefor determining the beamforming weights then processes the extractedmessage.

In an aspect, logical channels are classified into Control Channels andTraffic Channels. Logical Control Channels comprises Broadcast ControlChannel (BCCH), which is DL channel for broadcasting system controlinformation. Paging Control Channel (PCCH), which is DL channel thattransfers paging information. Multicast Control Channel (MCCH) which isPoint-to-multipoint DL channel used for transmitting MultimediaBroadcast and Multicast Service (MBMS) scheduling and controlinformation for one or several MTCHs. Generally, after establishing RRCconnection this channel is only used by UEs that receive MBMS (Note: oldMCCH+MSCH). Dedicated Control Channel (DCCH) is Point-to-pointbi-directional channel that transmits dedicated control information andused by UEs having an RRC connection. In aspect, Logical TrafficChannels comprises a Dedicated Traffic Channel (DTCH), which isPoint-to-point bi-directional channel, dedicated to one UE, for thetransfer of user information. In addition, a Multicast Traffic Channel(MTCH) for Point-to-multipoint DL channel for transmitting traffic data.

In an aspect, Transport Channels are classified into DL and UL. DLTransport Channels comprises a Broadcast Channel (BCH), Downlink SharedData Channel (DL-SDCH) and a Paging Channel (PCH), the PCH for supportof UE power saving (DRX cycle is indicated by the network to the UE),broadcasted over entire cell and mapped to PHY resources which can beused for other control/traffic channels. The UL Transport Channelscomprises a Random Access Channel (RACH), a Request Channel (REQCH), anUplink Shared Data Channel (UL-SDCH) and plurality of PHY channels. ThePHY channels comprise a set of DL channels and UL channels.

The DL PHY channels comprises: Common Pilot Channel (CPICH);Synchronization Channel (SCH); Common Control Channel (CCCH); Shared DLControl Channel (SDCCH); Multicast Control Channel (MCCH); Shared ULAssignment Channel (SUACH); ACKnowledgement Channel (ACKCH); DL PhysicalShared Data Channel (DL-PSDCH); UL Power Control Channel (UPCCH); PagingIndicator Channel (PICH); Load Indicator Channel (LICH); The UL PHYChannels comprises: Physical Random Access Channel (PRACH); ChannelQuality Indicator Channel (CQICH); ACKnowledgement Channel (ACKCH);Antenna Subset Indicator Channel (ASICH); Shared Request Channel(SREQCH); UL Physical Shared Data Channel (UL-PSDCH); Broadband PilotChannel (BPICH).

In FIG. 6, a serving radio access network (RAN), depicted as an evolvedbase node (eNB) 600, has a computing platform 602 that provides meanssuch as sets of codes for causing a computer assign and facilitate userequipment independence in handling measurement gaps. In particular, thecomputing platform 602 includes a computer readable storage medium(e.g., memory) 604 that stores a plurality of modules 606-610 executedby a processor(s) 620. A modulator 622 controlled by the processor 620prepares a downlink signal for modulation by a transmitter 624, radiatedby antenna(s) 626. A receiver 628 receives uplink signals from theantenna(s) 626 that are demodulated by a demodulator 630 and provided tothe processor 620 for decoding. In particular, Means (e.g., module, setof codes) 606 are provided for wirelessly communicating on a sourcecarrier frequency. Means (e.g., module, set of codes) 608 are providedfor transmitting an assignment for a measurement gap on the sourcecarrier frequency. Means (e.g., module, set of codes) 610 is providedfor facilitating user equipment to independently determine to remaintuned to the source carrier frequency during at least a portion of themeasurement gap, and to selectively tune between the source carrierfrequency and a target carrier frequency during the measurement gap inaccordance with the independent determination

With continued reference to FIG. 6, a mobile station, depicted as userequipment (UE) 650, has a computing platform 652 that provides meanssuch as sets of codes for causing a computer to handle measurement gapsin an independent fashion. In particular, the computing platform 652includes a computer readable storage medium (e.g., memory) 654 thatstores a plurality of modules 656-662 executed by a processor(s) 670. Amodulator 672 controlled by the processor 670 prepares an uplink signalfor modulation by a transmitter 674, radiated by antenna(s) 676 asdepicted at 677 to the eNB 600. A receiver 678 receives downlink signalsfrom the eNB 600 from the antenna(s) 676 that are demodulated by ademodulator 680 and provided to the processor 670 for decoding. Inparticular, means (e.g., module, set of codes) 656 are provided forwirelessly communicating on a source carrier frequency. Means (e.g.,module, set of codes) 658 are provided for receiving an assignment for ameasurement gap on the source carrier frequency. Means (e.g., module,set of codes) 660 are provided for independently determining to remaintuned to the source carrier frequency during at least a portion of themeasurement gap. Means (e.g., module, set of codes) 662 are provided forselectively tuning between the source carrier frequency and a targetcarrier frequency during the measurement gap in accordance with theindependent determination.

When the embodiments are implemented in software, firmware, middlewareor microcode, program code or code segments, they can be stored in amachine-readable medium, such as a storage component. A code segment canrepresent a procedure, a function, a subprogram, a program, a routine, asubroutine, a module, a software package, a class, or any combination ofinstructions, data structures, or program statements. A code segment canbe coupled to another code segment or a hardware circuit by passingand/or receiving information, data, arguments, parameters, or memorycontents. Information, arguments, parameters, data, etc. can be passed,forwarded, or transmitted using any suitable means including memorysharing, message passing, token passing, network transmission, etc.

For a software implementation, the techniques described herein can beimplemented with modules (e.g., procedures, functions, and so on) thatperform the functions described herein. The software codes can be storedin memory units and executed by processors. The memory unit can beimplemented within the processor or external to the processor, in whichcase it can be communicatively coupled to the processor via variousmeans as is known in the art.

With reference to FIG. 7, illustrated is a system 700 that enableshandling measurement gaps. For example, system 700 can reside at leastpartially within user equipment (UE). It is to be appreciated thatsystem 700 is represented as including functional blocks, which can befunctional blocks that represent functions implemented by a processor,software, or combination thereof (e.g., firmware). System 700 includes alogical grouping 702 of electrical components that can act inconjunction. For instance, logical grouping 702 can include anelectrical component for wirelessly communicating on a source carrierfrequency 704. Moreover, logical grouping 702 can include an electricalcomponent for receiving an assignment for a measurement gap on thesource carrier frequency 706. Further, logical grouping 702 can includean electrical component for independently determining to remain tuned tothe source carrier frequency during at least a portion of themeasurement gap 708. In addition, logical grouping 702 can include anelectrical component for selectively tuning between the source carrierfrequency and a target carrier frequency during the measurement gap inaccordance with the independent determination 710. Additionally, system700 can include a memory 712 that retains instructions for executingfunctions associated with electrical components 704-710. While shown asbeing external to memory 712, it is to be understood that one or more ofelectrical components 704-710 can exist within memory 712.

With reference to FIG. 8, illustrated is a system 800 that enablesassigning and facilitating use of measurement gaps. For example, system800 can reside at least partially within a base station. It is to beappreciated that system 800 is represented as including functionalblocks, which can be functional blocks that represent functionsimplemented by a processor, software, or combination thereof (e.g.,firmware). System 800 includes a logical grouping 802 of electricalcomponents that can act in conjunction. For instance, logical grouping802 can include an electrical component for wirelessly communicating ona source carrier frequency 804. In addition, logical grouping 802 caninclude an electrical component for transmitting an assignment for ameasurement gap on the source carrier frequency 806. Further, logicalgrouping 802 can include an electrical component for facilitating userequipment to independently determine to remain tuned to the sourcecarrier frequency during at least a portion of the measurement gap, andto selectively tune between the source carrier frequency and a targetcarrier frequency during the measurement gap in accordance with theindependent determination 808. Additionally, system 800 can include amemory 812 that retains instructions for executing functions associatedwith electrical components 804-808. While shown as being external tomemory 812, it is to be understood that one or more of electricalcomponents 804-808 can exist within memory 812.

In FIG. 9, a methodology or sequence of operations 900 is provided forhandling measurement gaps according to one aspect. UE operates at asource frequency (block 902). A measurement gap with a start time and astop time is received (block 904). The start time is the time when a UEis to switch to a target frequency, and the stop time is the time whenthe UE is to switch back to the source frequency. In other words, themeasurement gap is used by the UE to switch to a target frequency andperform one or more operations (e.g., take measurements, etc.). A UE isallowed to modify (1) the start time, (2) the stop time, or both (block906). When the start time is delayed, a late departure is implemented.When the stop time is moved forward, an early return is implemented. Itis noted that the UE is also allowed to not switch to the targetfrequency, thereby resulting in a cancelled departure (e.g., the case ofextending the departure time until the stop time). This approach enablesa smart UE from operating on to source frequency during a measurementgap, even if measurement is not needed. In an additional aspect, anUL-SCH retransmission that occurs during a measurement gap is canceled,regarded as NACK'ED and included in the total number of HARQtransmission attempts. Non-adaptive retransmission is performed afterthe gap (block 908). In a further aspect, if there was a measurement gapat the time of the PHICH for the last UL-SCH transmission, UE considersthat a HARQ ACK was received for that transmission. UE suspends HARQtransmissions and therefore a PDCCH is required to resumeretransmissions (block 910).

In FIG. 10, an apparatus 1002 is provided for utilizing a measurementgap. Means 1004 are provided for wirelessly communicating on a sourcecarrier frequency. Means 1006 are provided receiving an assignment for ameasurement gap on the source carrier frequency. Means 1008 are providedindependently determining to remain tuned to the source carrierfrequency during at least a portion of the measurement gap. Means 1010are provided selectively tuning between the source carrier frequency anda target carrier frequency during the measurement gap in accordance withthe independent determination.

In FIG. 11, an apparatus 1102 is provided for assigning a measurementgap. Means 1104 are provided wirelessly communicating on a sourcecarrier frequency. Means 1106 are provided transmitting an assignmentfor a measurement gap on the source carrier frequency. Means 1108 areprovided facilitating user equipment to independently determine toremain tuned to the source carrier frequency during at least a portionof the measurement gap and to selectively tune between the sourcecarrier frequency and a target carrier frequency during the measurementgap in accordance with the independent determination.

By benefit of the foregoing, it should be appreciated that various rulesfor handling measurement gaps can be implemented according to differentapproaches according to various aspects. First, if a PDCCH is receivedbefore measurement gap requesting an UL-SCH transmission during the gap,then the UE can perform measurement or perform the related UL-SCHtransmission; also UE may decode a PDCCH+PDSCH addressed to itself andtransmitted during a gap. Second, if a semi-persistent DL-SCHtransmission or UL-SCH transmission overlaps with gap, then the UE canperform measurement or perform SCH transmission. Third, if a UL ACK/NAKneeds to be sent during a measurement gap, or a DL ACK/NAK is expected,during a measurement gap, then the UE can perform measurement orsend/receive ACK/NAK. Fourth, if part of the end of a TTI bundleoverlaps with a measurement gap (for example, with a bundle of size 4,then 1, 2 or 3 subframes overlap), then the UE can perform measurementor transmit the part of the bundle that does not overlap with themeasurement gap. According to one aspect, the UE regards the bundle asnegatively acknowledged (NAKed) in any case, which may lead to uselessbundle transmission. In another aspect, the UE may consider the bundleas positively acknowledged (Ack) if at least one transmission occurredfor the bundle. In another aspect, the whole bundle may be cancelled andregarded as NAKed. Fifth, if a Scheduling Request(SR), SoundingReference Signal (SRS) or CQI report need to be transmitted during ameasurement gap, then the UE can perform the measurement gap or transmitsuch data on the associated PUCCH/PUSCH resource. Sixth, if a PRACHneeds to be transmitted during a measurement gap, then the UE canperform the measurement or transmit PRACH. In one aspect, eNB initiatedRACH is separated from UE initiated RACH. Seventh, if a Random AccessResponse window or any subsequent transmission part of the random accessprocedure, overlaps with a measurement gap, then the UE can avoid thePRACH to avoid the above overlap. Alternatively, the UE can always sendPRACH without considering present or future gaps and then must look forRandom Access Response (RAR). The UE can always send PRACH withoutlooking at future gaps and if above happens perform the measurement.Eighth, if a first UL-SCH first transmission (Message 3) may bescheduled during a measurement gap. The UE can avoid the PRACH thatcould lead to that Message 3 being scheduled in order to perform themeasurement. The UE can perform message 3 transmission and ignore themeasurement. The UE can cancel message 3 and perform measurement if thathappens. Ninth, if a contention resolution message may be receivedduring a measurement gap, then the UE can look for the contentionresolution or perform measurement gap. In one aspect, the UE looksforward to avoid such case and not transmit PRACH then.

What has been described above includes examples of the various aspects.It is, of course, not possible to describe every conceivable combinationof components or methodologies for purposes of describing the variousaspects, but one of ordinary skill in the art may recognize that manyfurther combinations and permutations are possible. Accordingly, thesubject specification intended to embrace all such alterations,modifications, and variations that fall within the spirit and scope ofthe appended claims.

In particular and in regard to the various functions performed by theabove described components, devices, circuits, systems and the like, theterms (including a reference to a “means”) used to describe suchcomponents are intended to correspond, unless otherwise indicated, toany component which performs the specified function of the describedcomponent (e.g., a functional equivalent), even though not structurallyequivalent to the disclosed structure, which performs the function inthe herein illustrated exemplary aspects. In this regard, it will alsobe recognized that the various aspects include a system as well as acomputer-readable medium having computer-executable instructions forperforming the acts and/or events of the various methods.

In addition, while a particular feature may have been disclosed withrespect to only one of several implementations, such feature may becombined with one or more other features of the other implementations asmay be desired and advantageous for any given or particular application.To the extent that the terms “includes,” and “including” and variantsthereof are used in either the detailed description or the claims, theseterms are intended to be inclusive in a manner similar to the term“comprising.” Furthermore, the term “or” as used in either the detaileddescription of the claims is meant to be a “non-exclusive or”.

Furthermore, as will be appreciated, various portions of the disclosedsystems and methods may include or consist of artificial intelligence,machine learning, or knowledge or rule based components, sub-components,processes, means, methodologies, or mechanisms (e.g., support vectormachines, neural networks, expert systems, Bayesian belief networks,fuzzy logic, data fusion engines, classifiers . . . ). Such components,inter alia, can automate certain mechanisms or processes performedthereby to make portions of the systems and methods more adaptive aswell as efficient and intelligent. By way of example and not limitation,the evolved RAN (e.g., access point, eNode B) can infer or predict whena robust or augmented check field has been employed.

As used in this application, the terms “component”, “module”, “system”,and the like are intended to refer to a computer-related entity, eitherhardware, a combination of hardware and software, software, or softwarein execution. For example, a component may be, but is not limited tobeing, a process running on a processor, a processor, an object, anexecutable, a thread of execution, a program, and/or a computer. By wayof illustration, both an application running on a server and the servercan be a component. One or more components may reside within a processand/or thread of execution and a component may be localized on onecomputer and/or distributed between two or more computers.

The word “exemplary” is used herein to mean serving as an example,instance, or illustration. Any aspect or design described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other aspects or designs.

Furthermore, the one or more versions may be implemented as a method,apparatus, or article of manufacture using standard programming and/orengineering techniques to produce software, firmware, hardware, or anycombination thereof to control a computer to implement the disclosedaspects. The term “article of manufacture” (or alternatively, “computerprogram product”) as used herein is intended to encompass a computerprogram accessible from any computer-readable device, carrier, or media.For example, computer readable media can include but are not limited tomagnetic storage devices (e.g., hard disk, floppy disk, magnetic strips. . . ), optical disks (e.g., compact disk (CD), digital versatile disk(DVD). . . ), smart cards, and flash memory devices (e.g., card, stick).Additionally it should be appreciated that a carrier wave can beemployed to carry computer-readable electronic data such as those usedin transmitting and receiving electronic mail or in accessing a networksuch as the Internet or a local area network (LAN). Of course, thoseskilled in the art will recognize many modifications may be made to thisconfiguration without departing from the scope of the disclosed aspects.

Various aspects will be presented in terms of systems that may include anumber of components, modules, and the like. It is to be understood andappreciated that the various systems may include additional components,modules, etc. and/or may not include all of the components, modules,etc. discussed in connection with the figures. A combination of theseapproaches may also be used. The various aspects disclosed herein can beperformed on electrical devices including devices that utilize touchscreen display technologies and/or mouse-and-keyboard type interfaces.Examples of such devices include computers (desktop and mobile), smartphones, personal digital assistants (PDAs), and other electronic devicesboth wired and wireless.

In view of the exemplary systems described supra, methodologies that maybe implemented in accordance with the disclosed subject matter have beendescribed with reference to several flow diagrams. While for purposes ofsimplicity of explanation, the methodologies are shown and described asa series of blocks, it is to be understood and appreciated that theclaimed subject matter is not limited by the order of the blocks, assome blocks may occur in different orders and/or concurrently with otherblocks from what is depicted and described herein. Moreover, not allillustrated blocks may be required to implement the methodologiesdescribed herein. Additionally, it should be further appreciated thatthe methodologies disclosed herein are capable of being stored on anarticle of manufacture to facilitate transporting and transferring suchmethodologies to computers. The term article of manufacture, as usedherein, is intended to encompass a computer program accessible from anycomputer-readable device, carrier, or media.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein, will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

1. A method for utilizing a measurement gap, comprising: wirelesslycommunicating on a source carrier frequency; receiving an assignment fora measurement gap on the source carrier frequency; independentlydetermining to remain tuned to the source carrier frequency during atleast a portion of the measurement gap; and selectively tuning betweenthe source carrier frequency and a target carrier frequency during themeasurement gap in accordance with the independent determination.
 2. Themethod of claim 1, further comprising: independently determining to tuneaway from the source frequency later than the beginning of themeasurement gap; and tuning from the source to the target carrierfrequency after a start time assigned to the measurement gap.
 3. Themethod of claim 1, further comprising: independently determining to tuneback to the source frequency earlier than the end of the measurementgap; and tuning from the target to the source carrier frequency before astop time assigned to the measurement gap.
 4. The method of claim 3,further comprising: independently determining to depart tune away fromthe source frequency later than the beginning of the measurement gap;and tuning from the source to the target carrier frequency after a starttime assigned to the measurement gap.
 5. The method of claim 1, furthercomprising: independently determining to cancel departure from thesource frequency during the measurement gap; and remaining tuned to thesource carrier frequency during the measurement gap.
 6. The method ofclaim 1, further comprising: receiving and processing a downlinktransmission from a base station operating on the source frequencyduring an independently determined portion of the measurement gap. 7.The method of claim 6, wherein the downlink transmission is PDCCH(physical downlink control channel) or PDSCH (physical downlink sharedchannel).
 8. The method of claim 1, further comprising: performing anuplink shared channel (UL-SCH) transmission that is scheduled to occurduring the measurement gap;
 9. The method of claim 1, furthercomprising: receiving Hybrid Automatic-Repeat-Request (HARQ)acknowledgement (ACK/NAK) when HARQ feedback collides with a measurementgap.
 10. The method of claim 1, further comprising performing a PRACHtransmission that collides with a measurement gap.
 11. The method of 10,further comprising: determining whether to perform PRACH based onpotential collision of subsequent transmissions related to the RandomAccess Procedure with a measurement gap.
 12. The method of claim 1,further comprising performing transmission of a selected one ofScheduling Request, Sounding Reference Signal and CQI (channel qualityindicator) report, when it collides with a measurement gap.
 13. At leastone processor for utilizing a measurement gap, comprising: a firstmodule for wirelessly communicating on a source carrier frequency; asecond module for receiving an assignment for a measurement gap on thesource carrier frequency; a third module for independently determiningto remain tuned to the source carrier frequency during at least aportion of the measurement gap; and a fourth module for selectivelytuning between the source carrier frequency and a target carrierfrequency during the measurement gap in accordance with the independentdetermination.
 14. A computer program product for utilizing ameasurement gap, comprising: a computer-readable storage mediumcomprising, a first set of codes for causing a computer to wirelesslycommunicate on a source carrier frequency; a second set of codes forcausing the computer to receive an assignment for a measurement gap onthe source carrier frequency; a third of codes for causing a computer toindependently determine to remain tuned to the source carrier frequencyduring at least a portion of the measurement gap; and a fourth of codesfor causing a computer to selectively tune between the source carrierfrequency and a target carrier frequency during the measurement gap inaccordance with the independent determination.
 15. An apparatus forutilizing a measurement gap, comprising: means for wirelesslycommunicating on a source carrier frequency; means for receiving anassignment for a measurement gap on the source carrier frequency; meansfor independently determining to remain tuned to the source carrierfrequency during at least a portion of the measurement gap; and meansfor selectively tuning between the source carrier frequency and a targetcarrier frequency during the measurement gap in accordance with theindependent determination.
 16. An apparatus for utilizing a measurementgap, comprising: a transmitter for wirelessly communicating on a sourcecarrier frequency; a receiver for receiving an assignment for ameasurement gap on the source carrier frequency; and a computingplatform for independently determining to remain tuned to the sourcecarrier frequency during at least a portion of the measurement gap,wherein the computing platform is further for selectively tuning thereceiver between the source carrier frequency and a target carrierfrequency during the measurement gap in accordance with the independentdetermination.
 17. The apparatus of claim 16, wherein the computingplatform is further for independently determining to tune away from thesource frequency later than the beginning of the measurement gap; andthe computing platform is further for tuning the receiver from thesource to the target carrier frequency after a start time assigned tothe measurement gap.
 18. The apparatus of claim 16, wherein thecomputing platform is further for independently determining to tune backto the source frequency earlier than the end of the measurement gap; andthe computing platform is further for tuning the receiver from thetarget to the source carrier frequency before a stop time assigned tothe measurement gap.
 19. The apparatus of claim 18, wherein thecomputing platform is further for independently determining to departtune away from the source frequency later than the beginning of themeasurement gap; and the computing platform is further for tuning thereceiver from the source to the target carrier frequency after a starttime assigned to the measurement gap.
 20. The apparatus of claim 16,wherein the computing platform is further for independently determiningto cancel departure from the source frequency during the measurementgap; and wherein the computing platform is further for remaining tunedto the source carrier frequency during the measurement gap.
 21. Theapparatus of claim 16, wherein the computing platform is further forreceiving and processing a downlink transmission from a base stationoperating on the source frequency during an independently determinedportion of the measurement gap.
 22. The apparatus of claim 21, whereinthe downlink transmission is PDCCH (physical downlink control channel)or PDSCH (physical downlink shared channel).
 23. The apparatus of claim16, wherein the transmitter is further for performing an uplink sharedchannel (UL-SCH) transmission that is scheduled to occur during themeasurement gap;
 24. The apparatus of claim 16, wherein the receiver isfurther for receiving Hybrid Automatic-Repeat-Request (HARQ)acknowledgement (ACK/NAK) when HARQ feedback collides with a measurementgap.
 25. The apparatus of claim 16, wherein the transmitter is furtherfor performing a PRACH transmission that collides with a measurementgap.
 26. The apparatus of 25, wherein the computing platform is furtherfor determining whether to perform PRACH based on potential collision ofsubsequent transmissions related to the Random Access Procedure with ameasurement gap.
 27. The apparatus of claim 16, wherein the transmitteris further for performing transmission of a selected one of SchedulingRequest, Sounding Reference Signal and CQI (channel quality indicator)report, when it collides with a measurement gap.
 28. A method forassigning a measurement gap, comprising: wirelessly communicating on asource carrier frequency; transmitting an assignment for a measurementgap on the source carrier frequency; and facilitating user equipment toindependently determine to remain tuned to the source carrier frequencyduring at least a portion of the measurement gap and to selectively tunebetween the source carrier frequency and a target carrier frequencyduring the measurement gap in accordance with the independentdetermination.
 29. The method of claim 28, wherein user equipment canindependently determine to tune away during a beginning portion, a midportion, an ending portion, an entire portion, or to not tune away atall.
 30. The method of claim 28, further comprising transmitting adownlink transmission during the measurement gap in expectation thatuser equipment has remained tuned to the source frequency.
 31. Themethod of claim 30, wherein the downlink transmission is PDCCH (physicaldownlink control channel) or PDSCH (physical downlink shared channel).32. The method of claim 28, further comprising receiving an uplinkshared channel (UL-SCH) transmission from user equipment that isscheduled to occur during the measurement gap;
 33. The method of claim28, further comprising: transmitting Hybrid Automatic-Repeat-Request(HARQ) acknowledgement (ACK/NAK) when HARQ feedback collides with ameasurement gap.
 34. The method of claim 28, further comprisingreceiving a PRACH transmission from user equipment that collides with ameasurement gap.
 35. The method of claim 28, further comprisingreceiving transmission from user equipment of a selected one ofScheduling Request, Sounding Reference Signal and CQI (channel qualityindicator) report, when it collides with a measurement gap.
 36. At leastone processor for assigning a measurement gap, comprising: a firstmodule for wirelessly communicating on a source carrier frequency; asecond module for transmitting an assignment for a measurement gap onthe source carrier frequency; and a third module for facilitating userequipment to independently determine to remain tuned to the sourcecarrier frequency during at least a portion of the measurement gap andto selectively tune between the source carrier frequency and a targetcarrier frequency during the measurement gap in accordance with theindependent determination.
 37. A computer program product for assigninga measurement gap, comprising: a computer-readable storage mediumcomprising, a first set of codes for causing a computer to wirelesslycommunicate on a source carrier frequency; a two set of codes forcausing the computer to transmit an assignment for a measurement gap onthe source carrier frequency; and a third of codes for causing acomputer to facilitate user equipment to independently determine toremain tuned to the source carrier frequency during at least a portionof the measurement gap, and to selectively tune between the sourcecarrier frequency and a target carrier frequency during the measurementgap in accordance with the independent determination.
 38. An apparatusfor assigning a measurement gap, comprising: means for wirelesslycommunicating on a source carrier frequency; means for transmitting anassignment for a measurement gap on the source carrier frequency; andmeans for facilitating user equipment to independently determine toremain tuned to the source carrier frequency during at least a portionof the measurement gap, and to selectively tune between the sourcecarrier frequency and a target carrier frequency during the measurementgap in accordance with the independent determination.
 39. An apparatusfor assigning a measurement gap, comprising: a receiver for wirelesslycommunicating on a source carrier frequency; a transmitter fortransmitting an assignment for a measurement gap on the source carrierfrequency; and a computing platform for independently determining toremain tuned to the source carrier frequency during at least a portionof the measurement gap, wherein the user equipment selectively tunes itstransmitter between the source carrier frequency and a target carrierfrequency during the measurement gap in accordance with its independentdetermination.
 40. The apparatus of claim 39, wherein user equipment canindependently determine to tune away during a beginning portion, a midportion, an ending portion, an entire portion, or to not tune away atall.
 41. The apparatus of claim 39, wherein the transmitter is furtherfor transmitting a downlink transmission during the measurement gap inexpectation that user equipment has remained tuned to the sourcefrequency.
 42. The apparatus of claim 41, wherein the downlinktransmission is PDCCH (physical downlink control channel) or PDSCH(physical downlink shared channel).
 43. The apparatus of claim 39,wherein the receiver is further for receiving an uplink shared channel(UL-SCH) transmission from user equipment that is scheduled to occurduring the measurement gap;
 44. The apparatus of claim 39, wherein thetransmitter is further for transmitting Hybrid Automatic-Repeat-Request(HARQ) acknowledgement (ACK/NAK) when HARQ feedback collides with ameasurement gap.
 45. The apparatus of claim 39, wherein the receiver isfurther for receiving a PRACH transmission from user equipment thatcollides with a measurement gap.
 46. The apparatus of claim 39, whereinthe receiver is further for receiving transmission from user equipmentof a selected one of Scheduling Request, Sounding Reference Signal andCQI (channel quality indicator) report, when it collides with ameasurement gap.